---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 12/11/18: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:13 AM - Re: Cheap bench supply? (C&K) 2. 07:49 AM - Re: Cheap bench supply? (Richard Girard) 3. 02:08 PM - Re: A brown-out alternative? (zwakie) ________________________________ Message 1 _____________________________________ Time: 04:13:22 AM PST US Subject: Re: AeroElectric-List: Cheap bench supply? From: C&K One can usually replace the analog current potentiometer with a multi position rotary switch and fixed resistors if preferred. I find that about 6 positions suits my bench supply just fine. Ken On 10/12/2018 3:29 PM, Charlie England wrote: > > > On Tue, Nov 13, 2018 at 4:59 PM Charlie England > wrote: > > Anyone have experience with the recent ebay offerings for cheap > lab supplies? Example below. I tried searching my old AEC emails, > but the most recent reference I found was for a much more > expensive model. It'll get minimal use; just final checkout of my > project's wiring and then rare uses after that, so don't want to > spend $hundreds. > 0-30v/0-10a bench supply > > > Thanks, > > Charlie > > > Well, I said I'd publish a pirep once I received the unit, so here we go. > > The unit seems to work just fine, with a couple of 'idiosyncrasies'. > The controls are analog, as you'd expect from the pairs of coarse & > fine adjustment knobs. The only frustrating thing is that current > limit is set by setting voltage to some reasonably low value, setting > current to minimum, shorting out the+ & - terminals, and then dialing > up the current knobs to the desired limit. Then remove the short and > connect your load. At loads less than the current set point, the > voltage display shows your set point voltage (actual output voltage). > The current display will vary between zero and the current set point, > depending on actual load. Once the current limit is reached, voltage > (and the displayed voltage, of course) falls to limit current to the > preset level. > > Behavior of the supply is as expected, but it is frustrating to not > see the actual current limit set point while in operation, until you > actually hit the limit. Since the knobs are unmarked, this requires > going back through the limit setting for each new work session, unless > you trust that the current limit knobs haven't been touched since the > last session. The ideal supply would have both set point and output > displays, but for my limited needs, I don't need to pay for ideal. :-) > > Assuming long term survival, I consider it a great value compared to > the $hundreds required for lab grade supplies. > > Charlie > > > Virus-free. www.avast.com > > > ________________________________ Message 2 _____________________________________ Time: 07:49:18 AM PST US From: Richard Girard Subject: Re: AeroElectric-List: Cheap bench supply? Get some number transfers so you can set the knobs to the same settings you require. Set the top to 11 and watch "Spinal Tap" for a giggle. :-} Rick On Tue, Dec 11, 2018 at 6:18 AM C&K wrote: > > One can usually replace the analog current potentiometer with a multi > position rotary switch and fixed resistors if preferred. I find that > about 6 positions suits my bench supply just fine. > Ken > > On 10/12/2018 3:29 PM, Charlie England wrote: > > > > > > On Tue, Nov 13, 2018 at 4:59 PM Charlie England > > wrote: > > > > Anyone have experience with the recent ebay offerings for cheap > > lab supplies? Example below. I tried searching my old AEC emails, > > but the most recent reference I found was for a much more > > expensive model. It'll get minimal use; just final checkout of my > > project's wiring and then rare uses after that, so don't want to > > spend $hundreds. > > 0-30v/0-10a bench supply > > < > https://www.ebay.com/itm/10A-Digital-DC-Power-Supply-Variable-Adjustable- Lab-Bench-Test-Equipment-Tool/202435783331?ssPageName=STRK%3AMEBIDX%3AIT& _trksid=p2060353.m1438.l2649 > > > > > > Thanks, > > > > Charlie > > > > > > Well, I said I'd publish a pirep once I received the unit, so here we g o. > > > > The unit seems to work just fine, with a couple of 'idiosyncrasies'. > > The controls are analog, as you'd expect from the pairs of coarse & > > fine adjustment knobs. The only frustrating thing is that current > > limit is set by setting voltage to some reasonably low value, setting > > current to minimum, shorting out the + & - terminals, and then dialing > > up the current knobs to the desired limit. Then remove the short and > > connect your load. At loads less than the current set point, the > > voltage display shows your set point voltage (actual output voltage). > > The current display will vary between zero and the current set point, > > depending on actual load. Once the current limit is reached, voltage > > (and the displayed voltage, of course) falls to limit current to the > > preset level. > > > > Behavior of the supply is as expected, but it is frustrating to not > > see the actual current limit set point while in operation, until you > > actually hit the limit. Since the knobs are unmarked, this requires > > going back through the limit setting for each new work session, unless > > you trust that the current limit knobs haven't been touched since the > > last session. The ideal supply would have both set point and output > > displays, but for my limited needs, I don't need to pay for ideal. :-) > > > > Assuming long term survival, I consider it a great value compared to > > the $hundreds required for lab grade supplies. > > > > Charlie > > > > < > https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_ campaign=sig-email&utm_content=webmail&utm_term=icon> > > > Virus-free. www.avast.com > > < > https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_ campaign=sig-email&utm_content=webmail&utm_term=link> > > > > > > =========== =========== =========== =========== =========== =========== > > -- =9CBlessed are the cracked, for they shall let in the light.=9D Groucho Marx ________________________________ Message 3 _____________________________________ Time: 02:08:48 PM PST US Subject: AeroElectric-List: Re: A brown-out alternative? From: "zwakie" I received the last bit today (DC/DC converter) and had some time to kill this evening, so I built the circuit and tested it successfully on the bench. I used a Ripca 2152C for the relay and this little critter as the buck-boost converter: https://www.ebay.ca/itm/6-35V-to-1-35V-DC-DC-Buck-Boost-Charger-Power-Converter-Module-With-AluminumSG-/123523715069?oid=112837380675 , along with the diode(s) previously recommended. It will be a little while before I reach the point with my panel upgrade to glass before I can confirm it really prevents a brownout. I will report back when the time comes (hopefully in 2-3 weeks from now). -------- Marcel Zwakenberg Europa XS TG || 912ULS || PH-SBR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486241#486241 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.